Dental matrix-retainer



Nov. 18, 1952 w. T. M AFEE DENTAL MATRIX-RETAINER Filed Oct. 17, 1951 William TMHfee Patented Nov. 18, 1952 UNITED STATES PATENT OFFICE DENTAL MATRIX-RETAINER William T. McAfee, Roanoke, Va.

Application October 17, 1951, Serial No. 251,730

11 Claims. 1

This invention relates to a clamp for holding a matrix strip against a plastic filling in a tooth while the filling hardens.

It is an object of the invention to provide a jaw type of clamp which will hold a matrix strip in position over the filled area of a tooth so that the filling may harden while held within the cavity being filled.

Another object of the invention is to provide a jaw type dental clamp that is easily installed and removed to hold a matrix strip in place.

A further object of the invention is to provide a jaw type clamp that has approximate semicircular shape jaw members that are interconnected by a cross yoke which is pivoted to one jaw member and slidably connected to the other jaw member and wherein the yoke projects beyond the slidably connected jaw and has a pivotally mounted cam disc thereon for engagement with the adjacent jaw for closing the jaws when the disc is rotated.

A still further object of the invention is to provide in such a clamp just described serrated ends on the jaws so that a flexible strip of matrix when inserted around a tooth being filled may be held in place by having the free ends held tightly by the serrated jaw ends pressing thereagainst and between the tooth being filled and next adjacent tooth.

A still further object of the invention is to provide, in such a clamp as above referred to, one of the jaws with a bifurcated end and the other jaw with a pivoted bifurcated head whereby a matrix strip may be held against the labial of a tooth being filled by the clamp being set so that one jaw presses against the matrix strip and the other jaw presses against the posterior of the tooth.

A yet still further object of the invention is to provide a dental matrix-retainer clamp that is easily installed by one hand and released by one hand and yet has a cam securing means which holds the jaws of the clamp in a clamped position.

Still further objects and the entire scope of applicability of the present invention will become apparent from the detailed description given hereinafter; it should be understood, however, that the detailed description and specific examples are given by way of illustration only and,

while indicating preferred embodiments of the invention, are not given by way of limitation, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.

the other parts of the clamp and For a more complete understanding of the invention reference may be had to the drawings in which:

' Fig. l is a perspective view of the dental matrix-retained with the jaws in partial open position and with a fixed bifurcated jaw end on one jaw and a pivoted head having a bifurcated surface on the other jaw;

Fig. 2 is a top plan view of the dental matrixretainer shown in Fig. 1;

Fig. 3 is a front elevation of a solid matrix strip such as used with the clamp shown in Fig. 1;

Fig. 4 is a perspective view of a dental matrixretainer such as shown in Fig. l but having serrated end portions on the jaw ends;

Fig. 5 is a side elevation of the dental matrixretainer shown in Fig. 4 depicting the jaws in full open position;

Fig. 6 is a fragmentary front elevation of the serrated end of one of the jaws of the retainer shown in Fig. 5 as viewed along the line 6-6;

Fig. 7 is a perspective view of a flexible plastic matrix strip as used with the retainer shown in Figures 4 and 5;

Fig. 8 is a perspective view of the retainer of Fig. 1 holding the solid matrix strip of Fig. 3 against the labial of a tooth;

Fig. 9 is a perspective view of the retainer of Figures 4 and 5 holding the flexible plastic matrix strip of Fig. 7 in place about a tooth being filled; and

Fig. 10 is a side view of the retainer in Fig. 9.

Throughout the description and the figures in the drawing like reference characters refer to similar parts or elements.

The dental matrix-retainer generally indicated at It] in Fig. 1 is a gingival clamp for retaining a solid matrix strip such as at ll, see Fig. 3, against the labial I 2 of a tooth I 3 as shown in Fig. 8.

The dental matrix-retainer generally indicated at 30 in Figures 4 and 5 is an interproximal clamp for retaining a flexible matrix strip 3| about tooth 32 in which a plastic filling such as at 33 toward the front edge thereof has been inserted and is held therein untilit hardens.

The gingival clamp Ill and the interproximal clamp 30 are of like construction except for the clamping portions, per se, at the ends of the jaws to be later described.- The gingival clamp or matrix-retainer l0 has two jaws l4 and iii of general semi-circular shape having off-set ends I 4 and I5 which are apertured and held pivotally together by a pivot pin 16. The jaws M and [5 are of relatively thin metal stock a are are adapted to be sterilized along with the other instruments used by the dentist. The outer end of jaw M has attached a head member IT by means of a pivot pin H3 and this head I! is adapted to pivot about the end of jaw l4. Head I1 is formed of a folded metal strip so as to provide bifurcated portions 9--|9 which diverge outwardly at each side beyond a common plane containing the jaw members l4 and I5. It will be noted that a recess portion I9 is thus formed between the bifurcated portions |9|9 on pivotal head Head is thus adapted to press against and hold in place an arcuate matrix-retainer such as shown in Figures 3 and 8.

The end of jaw has formed thereon bi furcated portions -20 which diverge outwardly at each side beyond the common plane containing jaw members l4 and I5. .Ihe e x treme ends 20' of bifurcated portions 23 are P inted and serve. to g against. the. p sterior of a'tooth such as is when the clamp s shown in'pla'ce in Figure '8. It will be observed that the bifurcated portions |.9--|9 on head I! and the bifurcated portions 26- 2% on jaw l5 project .and I5. One end of the yoke members 22-22 is 'pivotallybon'ne'cted by 'a pivot pin 23 intermediate the ends of jaw l5 and to one side of the center of jaw l5 towards the pivotal connection of the jaws at It as best shown in the clamp in Figure 5. The other end of each yoke member 22-22 projects beyond the jaw M as at 22'. Each of the bars 22 is slotted at 22" adjacent the jaw I4 and towards the projectin end 22' with the slots extending lengthwise of the bars 22. These slots 22" are slidably received by a pin .24 fixed in jaw H3 in a position thereon opposite to the pivot pin 23 in jaw 5 whereby the yoke members 22-22 forming yoke 2| are slidably connected to jaw l4.

Mounted between the projecting portions 22 "of the yoke 2| is a disc member generally in- .dicated at 25 of approximate circular shape and pivotally connected to the projecting bar portions 22' by a common pivot pin 23.

Disc 25 has a raised cam surface at 2! along a portion of its edge; a circular recess portion 28 in a portion of the edge thereof corresponding in curvature t'o'the arcuate jaw 14 and adapted to receive the jaw l4 therein; and a knurled surface 29 on the edge thereof all as best shown in Figure 5. When t at 34 serratedjas shown by the serrations 35 in Figure 6.

vIn applying a plastic filling such as to an anterior tooth, it has been the practice for the dentist to hold with his fingers the matrix-retainer, such as the flexible strip 3|, around the area of the filling 33., see Figure 9, until the filling hardens. This is not only tedious but eonsun'ies valuable time of the dentist. By this inyention a simple :yetpositive acting matrix-retainer has been devised for not only holding a flexible matrix-retainer in proper place but also a solid arcuate matrix-retainer such as the typical retainer shown in Figure 3. A number of such retainer plates may be provided having various curvatures and being of various sizes adaptable to fit the particular contour of the labial portion of a tooth.

In Figure 8 a plastic filling has been inserted in a cavity to be filledin the labial. portion of tooth l3. It is desired to hold this filling tightly in place until it hardens. A matrix-retainer such as H in Figure 3 is selected that conforms to the size and curvature of the labial portion of the tooth in which the filling is being made. This labial clamp is inserted as shown in Figure 8.

bifurcated ends 2020 and their points 20' 'rest against the posterior portion of the tooth l3 .while the ifu ca e Portion I -4. 0: pi o head are placed against the outer surface of plate H and then disc 25 is rotated to bringth'je cam portion 2! thereonagainst the adjacent jaw l4 thus tending to close the jaws M and |5 an d to hold the dental matrix-retainer II in place.

In Figures 9 and 10 where'a plastic filling such as at 33 in the edge of an anterior tooth is being made, the flexible matrix-retainer or strip 3| is placed about tooth 32 having filling 33 therein and the ends of the strip as at 3| are brought over against the next adjacent tooth. The interproximal clamp 30 is placed with the serrated jaw ends 34 that lie in the plane of the clamp 30 so that the strip is wedged in between tooth 32 and the next'adjacent tooth. I In Figure 10 there is best shown the position of the serrated ends 34 on jaws Mand l5 holding the strip 3| in place when the cam portion 21 ofdisc 25 has been rotated so as to urge the jaw M towards closing position with the other jaw Hi. In installing the clamps as here shown, the dentist can easily hold in place the matrix-retainer with one hand while the other hand manipulates the matrix-retainer into place and sets up :on the jaws by easily rotating the disc 25 having the cam surface thereon with a finger or thumb of the hand holding the clamp. 7

Since it is obvious that certain further changes can be made in the foregoing constructionswithout departin from the spirit and scope of this invention, it is intended that all matter shown in the accompanying drawings or described here inbefore shall be interpreted as illustrative and not in a limiting sense.

I claim as my invention:

1. A dental matrix-retainer comprising a first and a second jaw pivotally connected, a yoke pivotally connected to the first jaw and slidably connected to the second jaw and having a portion of the yoke at the .slidable connection-ex.- tending beyond saidsecond jaw, a disc pivotally connected to said extending yoke portion and having a cam surface engageable with said second jaw for closing said jaws when said disc is rotated. Y

2. A dental matrix-retainer comprising a first and a second jaw each of arcuate shape and pivotally connected, a yoke pivotally connected to the first jaw and sl-idably connected to the second jaw and having a portion of the yoke at the slidable collection-extending beyond said second jaw, a disc pivotally connected to said extending yoke portion and having a ca'm surface engageabie with said second jaw for closing said jaws said disc is rotated. 1i

3. A dental matrix-retainer of the character described in claim 2 where said arcuate jaws are each of a semi-circular shape and are pivotally connected at one end thereof.

4. A dental matrix-retainer comprising a first and a second jaw pivotally connected, a yoke comprising a first and a second member extending parallel to each other along opposite sides of said jaws and being pivotally conected by a common pivot at one end thereof to the first jaw and slidably connected by a common connector to the second jaw, said yoke members having a portion thereof projecting beyond said second jaw and forming a slot therebetween, a disc mounted in said slot formed between said projecting members and pivotally connected by a common pivot to said projecting members, said disc having a cam surface thereon engageable with said second jaw for closing said jaws when said disc is rotated.

5. A dental matrix-retainer comprising a first and a second jaw pivotally connected, said jaws being of semi-circular shape, a yoke pivotally connected to the first jaw and slidably connected to the second jaw and having a portion of the yoke at the slidable connection extending beyond said second jaw, a disc pivotally connected to said extending yoke portion and having a cam surface engageable with said second jaw for closing said jaws when said disc is rotated, said disc having a circular recess in a portion thereof conforming to the second semi-circular jaw and within which said second jaw rests when said jaws are wide open and a knurled surface on a portion of said disc.

6. A dental matrix-retainer comprising a first and a second jaw each of arcuate shape and pivotally connected so as to lie in a common plane, each of said jaws ends opposite to the pivotal connection having serrated end portions lying in said common plane containing the jaws and adapted to abut when said jaws are closed, a yoke pivotally connected to the first jaw and slidably connected to the second jaw and having a portion of the yoke at the slidable connection extending beyond said second jaw, a disc pivotally connected to said extending yoke portion and having a cam surface engageable with said second jaw for closing said jaws when said disc is rotated.

'7. A dental matrix-retainer comprising two jaws each of arcuate shape and pivotally connected so as to lie in a common plane, one of said jaws having a bifurcated end with the bifurcated portions thereof extending outward from the common plane containing said jaws, the other of said jaws having a head pivotally connected to the end thereof, said pivotal head having a bifurcated end portion with the bifurcations extending to each side of said common plane, a yoke pivotally connected to one of said jaws and slidably connected to the other of said jaws with the yoke projecting outward beyond said slidable connection, a disc pivotally connected to said extending yoke portion and lying in said common plane and having a cam surface engageable with said jaw slidably connected to the yoke for closing said jaws when said disc is rotated.

8. A dental matrix-retainer comprising flat pivotal jaws lying in a common plane, said jaws being of semi-circular shape and having serrated end portions adapted to abut when said jaws are closed and lying in the common plane containing said jaws, a pair of fiat yoke members disposed on opposite sides of said jaw members and having one end thereof pivotally connected to one of said jaws and the other ends projecting beyond the other jaw and slidably connected therewith, a disc member between said projecting ends of the yoke members and pivotally connected thereto by a common pivot, said disc member having a cam surface portion thereon for engagement with the adjacent jaw member for pivoting said jaws to closed position when said disc is pivoted, said disc having a recessed circular portion in the edge thereof adapted to receive said adjacent jaw when the jaws are opened and a knurled edge portion on said disc.

9. A dental matrix-retainer of the character described in claim 8 wherein said yoke members have slotted apertures extending lengthwise thereof at the projecting ends and adjacent said slidably connected jaw, said slidably connected jaw has a transverse pin fixed thereto adapted to be received within said slotted apertures in said yoke members.

10. A dental matrix-retainer comprising fiat pivoted jaws lying in a common plane, said jaws being of semi-circular shape, one of said jaws having a bifurcated end with the bifurcated portions thereof extending outward from the common plane containing said jaws, the other of said jaws having a head pivotally connected to the end thereof, said pivoted head having a bifurcated end portion with the bifurcations extending to each side of said common plane and opposed to the bifurcations on said first mentioned jaw, a pair of fiat yoke members disposed on opposite sides of said jaw members and having one end thereof pivotally connected to one of said jaws and the other ends projecting beyond the other jaw and slidably connected therewith, a disc member between said projecting ends of the yoke members and pivotally connected thereto by a common pivot, said disc member having a cam surface portion thereon for engagement with the adjacent jaw member for pivoting said jaws to closed position when said disc is pivoted, said disc having a recessed circular portion in the edge thereof adapted to receive said adjacent jaw when the jaws are opened and a knurled edge portion on said disc.

11. A dental matrix-retainer according to claim 10 wherein said yoke members have slotted apertures extending lengthwise thereof at the projecting ends and adjacent said slidably connected jaw, said slidably connected jaw has a transverse pin fixed thereto adapted to be received within said slotted apertures in said yoke members.

WILLIAM T. McAFEE.

No references cited. 

